Alarm Console in UIM will go into a loading state after loading more alarms in buffer (via scroll bar) 10-11 times, and then moving the slider to the top. This would require that there are at least 600 alarms in the alarm viewer. It can validated with history showing if there are not enough current alarms.
Release : 20.4
Component : UIM OPERATOR CONSOLE - ALARM VIEWER
Fixed with CU4 for 20.4.